Update README.md

Author: getsumio

README.md

@@ -221,3 +221,5 @@ below commands will be called:
 * ***Linux/MAC***: MD5, SHA1, SHA224, SHA256, SHA384, SHA512
 * ***GO***: MD4,MD5,SHA1,SHA224,SHA256,SHA384,SHA512,RMD160,SHA3-224,SHA3-256,SHA3-384,SHA3-512,SHA512-224,SHA512-256,BLAKE2s256,BLAKE2b256,BLAKE2b384,BLAKE2b512
 * ***OPENSSL***: MD4,MD5,SHA1,SHA224,SHA256,SHA384,SHA512,RMD160,SHA3-224,SHA3-256,SHA3-384,SHA3-512,SHA512-224,SHA512-256,BLAKE2s256,BLAKE2b512,SHAKE128,SHAKE256,SM3
+
+icon credit: https://www.flaticon.com/authors/freepik